A leadframe of this type is known from U.S. Pat. No. 5,554,569. This document describes a process for mechanically roughening the surface of a leadframe by bombardment with abrasive, microscopically small particles which include, inter alia, sand, silicon dioxide or aluminum dioxide.
The leadframe described in U.S. Pat. No. 5,554,569 can scarcely be produced economically, since a dry process has to be carried out in addition to the wet-chemical processes used to clean and improve the leadframe surface in a closed production line with baths arranged spatially in succession. Moreover, a cleaning step has to be provided for in order to remove the residues of blasting agents from the leadframe surface.
U.S. Pat. No. 5,554,569 also reports on bonding agents for improving the bonding between leadframe and plastic encapsulation. Moreover, it states that it is known that the bonding between leadframe and plastic can be improved by the targeted application of copper oxides to the leadframe. However, the abovementioned processes all have the drawback of being difficult to carry out.
Moreover, damage and unreliability still occur in operation with all of the semiconductor devices produced using the processes known from the prior art.
For these and other reasons there is a need for the present invention.